Staff: Mentor

Resistors are routinely rated up to 155C. What power levels are you talking about?

Caps are a different matter, depending on the value and type. Ceramic caps are rated up to 125C -- you just have to look at the tempco graph for each ceramic type in order to see if the variation will be tolerated by your circuit. If you can use X7R ceramic caps, they are pretty flat up to 125C.